Likelihood of enemy subs detecting a weapon launch
 

Does anyone know how the game models this? Will they always detect the transient or is it based on sonar values etc?

Can they detect incoming torpedos that are set to passive only?

Cannot tell you for sure one way or the other mate.

All I can give you is some sketchy "well this happened to me" stories

Whilst broadside to an enemy sub I have launched, and despite the fact that their sonar fix on me was very poor (well into the minus tens or twenties), they seemed to react straight away and counter launch and go active

However, I have launched on enemy subs when I am deep in their baffles (-50 on both their sonar figures)
In these cases I have seen them not react until my torps are within a few thousand yards

Just some anecdotal evidence :03:

I think its sonar based somewhere along the lines of +5 to +10 db on top of whatever your normal signature is. Either way in a lot of cases they are bound to hear the torpedo sooner or later as well but.

Yeah I can offer nothing beyond anecdotes as well, but if you fire from long range the escorts won't get a read on you. They may fire torpedoes in the general direction of the torpedo when they hear it, but those are easy enough to avoid. Close in launches are always detected, so use caution going head to head, even with older subs.

In config.txt is the parameter NoiseFromTransient = 5
probably this noise is attained to the basic noise of the torpedo during start.

passive probably does not increase its noise when start to search above the base noise

----
bad english sorry

welcome aboard!
 

This is pretty much accurate with my tests. Also I don't think that masking launch transient by your hull is modelled.

As for active vs passive torpedo detection, the only difference is that they can detect a ping from active torpedo even if they can't hear a passive one.